class Barrier

A synchronization barrier enables multiple threads to wait until all threads have all reached a particular point of execution before any thread continues.

Public Class Methods

new(count) click to toggle source

Initialize new barrier. The count argument specifies the number of threads that must call wait before any of them successfully return from the call. The value specified by count must be greater than zero.

For example

b = Barrier.new(3)
3.times do
  Thread.new do
    print 1
    b.wait
    print 2
  end
end
sleep(1)
puts

produce

# File lib/barrier.rb, line 25
def initialize(count)
  @count_max = count
  @count = 1
  @mutex = Mutex.new
  @lock = ConditionVariable.new
end

Public Instance Methods

wait() click to toggle source

The wait function shall synchronize participating threads at the barrier. The calling thread shall block until the required number of threads have called wait specifying the barrier.

# File lib/barrier.rb, line 35
def wait
  @mutex.synchronize do
    if @count < @count_max
      @count += 1
      @lock.wait(@mutex)
    else
      @count = 1
      @lock.broadcast
    end
  end
  nil
end